Fig. 1 Location of samples selected for the microstructure and tensile characterizations

Fig. 2 Microstructure of the Al-Mn-Mg-Sc alloy atomized powder: a OM image; b BSE image

Fig. 3 a XRD patterns of powder and SLM samples with building direction and scanning directions; b-e the amplification of XRD patterns

Fig. 4 OM images of the SLM Al-Mn-Mg-Sc samples with different laser energy densities: a, a1 Q = 58.3 J/mm3; b, b1 Q = 62.5 J/mm3; c, c1 Q = 66.7 J/mm3; d, d1 Q = 75 J/mm3; building direction: a-d; scanning direction: a1-d1

Fig. 5 BSE images of SLM Al-Mn-Mg-Sc samples (Q = 66.7 J/mm3): a, b building direction; c, d scanning direction

Fig. 6 OM images showing characteristic microstructures of SLM Al-Mn-Mg-Sc samples in building direction a, b and scanning direction c, d

Fig. 7 Tensile strength of the SLM and HT samples with various laser energy density: a calculated UTS, YS and ${\varepsilon }_{\mathrm{f}}$; b stress-strain curves during tensile test

Fig. 8 Inverse pole figure, kernel average misorientation of Al-Mn-Mg-Sc alloy (Q = 66.7 J/mm3): a, b IPF maps; c, d KAM maps; a, c building direction; b, d scanning direction

Fig. 9 Grain size distribution a, b and misorientation angle distribution c, d of SLM Al-Mn-Mg-Sc samples in building direction a, c and scanning direction (b, d)

Fig. 10 PFs showing the {100} crystallographic orientation of SLM Al-Mn-Mg-Sc samples in building direction a and scanning direction b; c standard (001) stereographic projectionFull size image

Fig. 11 ODF sections of φ = 0° in building direction a and scanning direction b; c position of typical texture components in the section of φ = 0°

Fig. 12 SEM image of building direction revealing a layered microstructure consisting of multiple grains: FEG, CEG and CDFull size image

Fig. 13 Morphologies of the different crystal structure in building direction: a, d FEG; b CD; c CEG; e contrast between FEG and CD; f contrast between FEG and CEG

Fig. 14 a High angle annular dark field (HAADF-TEM) image of FEG in building direction; b EDS mapping for Al, Mn, Mg, Si, Sc, Cu and Zn distributions

Fig. 15 TEM images of sample processed by SLM: a bright-field TEM image of the building direction; b SAED pattern from a, showing the diffraction patterns of phases

Fig. 16 BFTEM and HRTEM images of FEG zone in building direction: a high density dislocations in BFTEM; b, c detailed dislocation pile up group in HRTEM; d vacancies and thickness fringes in BFTEM; e, f detailed thickness fringes in HRTEM

Fig. 17 a HRTEM images of CEG zone showing the crystalline structure of precipitations in CEG zone; b matrix α-Al with FCC structure; c, f the transformation of α-Al matrix to Al3(Sc, Zr) particle; d, e Al3(Sc, Zr) particle with L12 structure